Flu and the Y chromosome

Disease and death caused by influenza virus are greater in human females than in males. But disease is more common in males from birth through age 15, after which more females are affected. In mice, genetic variation in the Y chromosome controls susceptibility to influenza virus infection (link to paper). Increased susceptibility does not correlate with increased viral replication, but an expanded pathogenic immune response in the lungs. A panel of mice (strain B6) with the Y chromosome from eleven different strains were used to determine the effect of infection. The mice fell into two groups with distinct high and low survival after intranasal infection with the mouse-adapted PR8 strain of influenza virus. These results show that variation in the Y chromosome influences survival after infection. Furthermore, the previously reported greater susceptibility of female B6 mice to influenza virus infection compared with male mice is due to the presence of the Y chromosome. Viral replication in the lung does not differ between mouse strains with high and low mortality. Increased mortality is associated with an increase in a type of T lymphocyte called gamma-delta T cells which produce interleukin 17. The latter is known to provoke lung-damaging inflammation. Differences in susceptibility of mice with different Y chromosomes has nothing to do with the immunosuppressive effects of testosterone. Exactly which genes on the Y chromosome affect influenza virus susceptibility are unkno...
Source: virology blog - Category: Virology Authors: Tags: Basic virology Information disease susceptibility influenza mice sex viral virus viruses Y chromosome Source Type: blogs